She began her career as an operetta singer in 1878 under the name Sophie Offeney on Carola Theatre in Leipzig. In 1879-1880 she worked in Mainz, 1880-85 at Residenz Theater in Dresden, 1886-87 at the Deutsches Theater in Amsterdam. In 1887 she came to the Thalia Theater in New York, but returned back to Germany and worked – still as an operetta singer – 1882-1892 at Friedrich-Wilhelm City Theatre in Berlin. After new studies by Schmidt in Vienna in 1893 was her debut on the opera stage as Leonore in “Fidelio” at the City Theatre in Gdansk. This was followed by guest appearances at the opera house in Leipzig and at the Kroll Opera in Berlin. 1895-96 she sang at the Opera House of Breslau and was then appointed to the Vienna Court Opera, where she sang her first role in 1896 as Pamina in “The Magic Flute.” By 1907, she was there in place of Amalie Materna a celebrated high dramatic soprano. She was a guest at the opera house in St. Petersburg (as Brünnhilde and as Elsa), at the National Opera of Budapest (1896 in a Wagner cycle and as Leonore in “Fidelio”, which took place performances in Hungarian) Garden and at Covent Opera in London, she performed at the 1897 at the Diamond Jubilee celebrations for Queen Victoria as Isolde and as Brünnhilde. In 1895 she was heard in Bremen in the biblical musical drama “Christ” by A. Rubinstein. From her stage repertoire addition, the Countess in “The Marriage of Figaro,” which Sandrina in “La Finta Giardiniera” by Mozart, Rachel in “La Juive,” by Halévy, the Selika and in Meyerbeer’s “Africaine,” Senta in “The Flying Dutchman” Elisabeth mention in “Tannhauser”. She was to a known concert and oratorio soloist. She has also appeared under the name Sedlmair-Offeney and Sedlmair-Rudinger. After completion of her career as a teacher, she lived in Hanover. – Her voluminous, dark timbre soprano was admired in the dramatic, especially in the Wagner repertoire. Other spelling of their name and first name: “Sophie”, “Sedlmayr” and “Sedlmayer”.
The records of the artist is very rare there are 13 tracks on G & T (Vienna, 1903-1904), some on Zonophone (Vienna, 1902, including a duet with Leo Slezak), also on Beka (around 1906), three the Janus brand (Parsifal).